The FBI is investigating a massive hack into Gawker Media, The Post has learned.

Federal investigators are expected to meet with Gawker Media CEO Nick Denton today after the massive weekend hack by a group called Gnosis paralyzed the media company’s Web site and temporarily forced it to stop publishing.

Gawker is a snarky site that dishes on the inside secrets and goings on in the media world through a variety of sites, including Gawker, Gizmodo and Jezebel.

Hackers had grabbed the passwords and e-mail addresses of 1.3 million of the 1.5 million registered users and publicly posted roughly 200,000 email addresses.

The sites were forced to stop publishing new material on Sunday and urged everyone who had used it to change their password.

A red-faced Denton admitted on his site: “We’re deeply embarrassed by this breach.”

The sites, however, were not able to allow customers to delete accounts by late Monday afternoon.

Some Gawker commentators were clearly angry that the first notice of a potential breach went out on Twitter Tweet.

Wrote one commentator: “I, too, would like to know why we weren’t informed immediately, the second this went up. This may come as a shock to you, but many of us who comment on Gawker don’t read Twitter unless we have to. We, the commenters, are your base — the Typhoid Marys of all of your articles, scoops and gossip alike, who bring in those new eyes you so desperately chase. Prank or not, y’all had a responsibility to warn us on the main page that there was a possibilityof a compromised system.”

Gawker temporarily disabled Facebook Connect servers and said it never stored Twitter account passwords. However, it told those who comment on Gawker items and use the same passwords on Twitter and Gawker to change both passwords.

The hacker group said that the Gawker site was chosen because of its “arrogance.”

Gawker had in the past been critical of the hacker group, 4Chan, which is linked to Anonymous, the group that had allegedly put MasterCard and others under cyber attacks.

“We need to improve our internal procedures for the sharing of administrative passwords. And improve the encryption of passwords in case the user database is ever compromised,” Denton told The Post via e-mail.

It was still early to tell if the hacking has done any long-term damage to the site since users were not yet able to delete their accounts.

Gawker said there was a spike in traffic on Sunday by people who were just logging onto the site without leaving comments.

“The kind of attention we got — which spiked Gawker.com traffic — is the kind we can do without,” said Denton.